Shoppers on Oxford Street are being warned about a new scam, being used to con them out of their money.
It involves women - normally members of Romanian gangs - fooling people into handing over cash in exchange for worthless metal rings.
Westminster Council wardens say the scam has now become so common they are dealing with several incidents a day.
More top news
Thousands of people turned out in Trafalgar Square for a free screening of Oscar nominated film The Salesman
A baby dolphin has been spotted swimming in the Thames near Embankment pier.
The Olympic champion released a statement after a newspaper alleged his American coach may have broken anti-doping rules.